mode ranging from -2V to +2V.
1) is this possible?
2) What about the gain control voltage. Does it's common mode voltage also need
to change accordingly or is a 0V CM always okay?
1. The absolute input voltage is +/-2V at VINP, while COMM needs to be at GND.
So if you bias the signal at some voltage other than 0V you are effectively
reducing the signal headroom by that amount.
2. The gain voltage interface is differential, as opposed to the signal voltage
interface which is single ended. The common mode voltage can be whatever you
like as long as the absolute voltage on each input is within the range -1.2V to